JPH0322558Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention relates to a reciprocating pump that performs pumping by reciprocating a plunger or a diaphragm, and in particular, to variably set the pump capacity in this type of pump. This invention relates to improvement of a drive device for. .

[Conventional technology]

Conventionally, various improvements have been made in this type of variable displacement reciprocating pump in order to solve problems such as a large load on the prime mover while the pump is being driven and troublesome stroke adjustment.

For example, as the above-mentioned improved pump structure,
A transmission frame body having a plunger formed on one side and a holder case disposed oppositely on the other side is provided, an eccentric cam having a ball bearing fitted on the outer periphery is positioned inside the transmission frame body, and the transmission frame body is A member that circumscribes the ball bearing at the discharge position is provided on the plunger side, and a spring holder that is biased toward the camshaft by a spring and is in pressure contact with the ball bearing is slidably mounted on the holder case. In addition, a device has been proposed in which a stroke adjustment screw is provided to regulate the forward and backward movement of the holder case to adjust the reciprocating movement of the plunger (Japanese Patent Publication No. 57-34466). With this configuration, the pressure of the pump itself is applied to the plunger provided on one side of the transmission frame, and the load on the prime mover is applied only to the spring pressure applied to the spring holder of the holder case provided on the other side of the transmission frame. By separating the motor and the eccentric cam, it is possible to reduce the load on the prime mover and the eccentric cam and to facilitate stroke adjustment.

[Problem that the invention attempts to solve]

However, in the pump constructed as described above, in order to separate the pressure of the pump itself applied to the prime mover from the spring pressure, the transmission frame body is constructed as a large-diameter frame member that can sufficiently allow the swinging of the eccentric cam. Moreover, there is a problem in that the structure of providing a spring holder to the transmission frame and adjusting its position is complicated. Furthermore, in this type of pump, the transmission frame rotates a knob to move the stroke adjustment screw for the maximum reciprocating distance K of the plunger, and the distance L between the stroke adjustment screw and the end of the holder case is set to be greater than or equal to K. If you defect,
You will have to move between them. Therefore, the discharge amount in this case is 100%, but if you turn the knob to shorten the interval L until it becomes 0, the load on the prime mover could previously be separated as spring pressure in the discharge stroke, but the opposite occurs. However, during the suction stroke, the spring pressure acts as a load on the prime mover.

Therefore, although this type of pump can overcome the above-mentioned conventional problems, it also has a complicated structure, and when the eccentric cam acts on the suction side as the reciprocating distance of the plunger is shortened, However, there are drawbacks such as a load due to spring pressure being applied to the prime mover and mechanical loss during suction being large.

Therefore, the purpose of the present invention is to simplify the stroke adjustment mechanism, reduce the load on the eccentric cam or the electric motor that drives the eccentric cam during the discharge stroke, and enable the pump to be manufactured compactly and at low cost. An object of the present invention is to provide a reciprocating pump drive device that can easily improve accuracy.

[Means for solving problems]

A reciprocating pump drive device according to the present invention includes an eccentric cam disposed so as to come into contact with a part of a reciprocating member whose one end is located on the side of the pump section during the pump discharge stroke, and the other end of the reciprocating member. an adjusting screw shaft that is screwed into the shaft so that it can move forward and backward and comes into contact with the eccentric cam during the pump suction stroke, and a stroke adjusting knob that holds the adjusting screw shaft so as to be slidable in the axial direction and engaged in the rotational direction. and an electric motor that rotationally drives the eccentric cam, in which a diaphragm is coupled to a pump portion side of the reciprocating member, and a space in which the eccentric cam is inserted and arranged on the opposite side. The stroke adjusting knob is arranged so as to be adjustable so as to come into contact with the end of the frame part on the axis of the reciprocating member at the end of the pump suction stroke, and It is characterized in that the threaded portion of the adjusting screw shaft that is screwed into the end portion is configured to have the same pitch as the threaded portion of the stroke adjusting knob, and to have an opposite threaded relationship.

[Effect]

According to the present invention, by configuring the stroke adjustment knob and each threaded part of the adjustment screw shaft to have an equal pitch and an opposite thread relationship, the stroke adjustment knob can adjust the interval between the frame part and the stroke adjustment knob. At the same time, the contact position between the eccentric cam and the adjustment screw shaft head is adjusted to determine the stroke of the moving member, and at the determined stroke end, the contact position between the end of the frame and the stroke adjustment knob is adjusted. Due to the abutment, stroke adjustment by the adjusting screw shaft can be easily and accurately achieved even while the pump is being driven, and protection against sudden back pressure from the diaphragm side can be easily and reliably achieved.

〔Example〕

Next, embodiments of a reciprocating pump drive device according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an embodiment in which the drive device of the present invention is applied to a diaphragm type reciprocating pump. That is, in FIG.
0 indicates a diaphragm head, and ball valves 1 are installed at the top and bottom of this diaphragm head 10, respectively.
A discharge pipe 16 and a suction pipe 18 with 2, 14 are installed. This diaphragm head 10
A coupling tool 22 is attached to one side of the diaphragm 20 mounted on the diaphragm 20, and the coupling tool 22 is coupled to one end of the reciprocating member 24. A space 26 is provided in the middle portion of the reciprocating member 24, and an eccentric cam 28 that rotates eccentrically in the axial direction of the reciprocating member 24 is inserted therein. This eccentric cam 28 is connected to the reciprocating member 24
The reciprocating member 24 is pivoted to a rotating shaft 30 that freely passes through the side surface of the reciprocating member 24 so as to be perpendicular to the axis of the reciprocating member 24 .
Although not shown, the rotating shaft 30 is held in a double-sided manner via two bearings attached to a casing 32 surrounding the reciprocating member 24, and furthermore, a drive shaft of an electric motor is connected to one end of the rotating shaft 30. be done. Further, the other end of the reciprocating member 24 has a female threaded portion 3.
4, and an adjusting screw shaft 36 is screwed thereto. The adjusting screw shaft 36 has a screw end 38 at one end protruding into the space 26 from the female screw section 34 to face the eccentric cam 28, and a shaft end 40 at the other end screwed into the casing 32. It is slidably fitted into the shaft portion of the stroke adjustment knob 42 .
In this case, for example, the shaft end 40 of the adjusting screw shaft 36 may be a combination of a square shaft portion and a square shaft hole.
is fitted to the stroke adjustment knob 42 so that it can engage with the stroke adjustment knob 42 in its rotational direction and rotate integrally therewith. In addition, the present invention is particularly characterized in that the threaded portion of the adjusting screw shaft 36 is configured to have an equal pitch with the threaded portion of the stroke adjusting knob 42 and to have a reverse thread relationship.

In the drive device of this embodiment configured in this manner, the reciprocating member 24 includes a rod portion 24a coupled to the diaphragm, and a frame portion 24b forming a space 26 into which the eccentric cam 28 is inserted.
A stepped portion 44 is formed at the joint between the rod portion 24a and the frame 24b. Then, the rod portion 24a faces the stepped portion 44.
A stopper 46 is provided that surrounds the reciprocating member 24 and that has one end fixed to the casing 32 to restrict the movement position of the reciprocating member 24 in the axial direction. That is, the position where the movement of the reciprocating member 24 is restricted by the stopper 46 is such that when the stepped portion 44 of the reciprocating member 24 comes into contact with the stopper 46, the displacement of the diaphragm 20 is maximized in the discharge direction within the diaphragm head 10. Set to be the top dead center of the maximum discharge state with displacement. It is preferable that a cushion member 48 is provided at the other end of the stopper 46 to reduce the impact when it comes into contact with the step portion 44.

Next, regarding the drive device having the above configuration, the first
The stroke adjustment operation and its operation will be explained based on the diagram. Now, by rotating the stroke adjustment knob 42 in a predetermined direction, the adjustment screw shaft 36 is advanced relative to the reciprocating member 24, as shown in FIG.
If the adjusting screw shaft 36 is positioned so that its threaded end 38 comes into contact with the eccentric cam 28, the threaded end 38 of the adjusting screw shaft 36 will always be in contact with the eccentric cam 28, and when the eccentric cam 28 rotates, it will move back and forth. Member 24
makes a reciprocating displacement with the maximum stroke, and the amount of displacement of the diaphragm 20 also becomes the maximum, making it possible to set the pump discharge amount to the maximum. Next, a detailed explanation will be given based on FIGS. 2 to 4. In addition,
FIG. 2 shows the adjusted state shown in FIG. 1, with the upper half of the reciprocating member 24 showing the maximum discharge stroke and the lower half showing the maximum suction stroke (see FIG. 1). The same applies to FIGS. 3 and 4 below.

Next, the stroke adjustment knob 42 is rotated in the opposite direction, the adjustment screw shaft 36 is moved back with respect to the reciprocating member 24, and the screw end 38 is positioned so as to gradually move away from the eccentric cam 28. in this case,
If the separation distance between the threaded end portion 38 and the eccentric cam 28 is 1/2 of the reciprocating displacement amount L caused by the maximum stroke of the reciprocating member 24, the reciprocating member 24 is a 1/2 stroke (see Figure 3), and the reciprocating displacement L
If it matches, the stroke will be 0 (see Figure 4). Therefore, by positioning the adjusting screw shaft 36 between the 0 stroke position and the maximum stroke position, the stroke of the reciprocating member 24 can be adjusted, thereby making it possible to obtain the required pump discharge characteristics. can.

In particular, what is noteworthy about this invention is the second
As shown in the lower half of the figure, when the eccentric cam 28 is in the rotational position indicating the end of the suction stroke (maximum suction), the reciprocating member 24 and the left end of the adjusting screw shaft 36 are connected to the outer periphery of the eccentric cam 28. When in contact with a surface, the right end shoulder portion of the frame portion 24b and the left end portion of the stroke adjustment knob 42 form a small gap α (for example, 0.1 mm).
The prerequisite is to adjust and assemble them so that they are relative to each other.

From the above-mentioned state, in the suction stroke shown in FIG. 3, the stroke adjustment knob 42 is rotated to move it forward, and the gap between the right end shoulder of the frame portion 24b and the left end of the stroke adjustment knob 42 becomes (L). /2+
α), stroke adjustment knob 4
2 and the adjustment screw shaft 36 are slidable in the axial direction,
Moreover, they are engaged in the rotational direction, and furthermore, both 42 and 3
Since the threaded portions at 6 and 6 are in a pitch relationship such as reverse threads, the stroke adjustment knob 42 moves forward by L/2 to the left and the adjustment screw shaft 36 moves back by L/2 to the right at the same time. , a gap of L/2 is created between the outer peripheral surface of the eccentric cam 28 and the left end of the adjusting screw shaft 36.

Therefore, when the eccentric cam 28 rotates clockwise, the eccentric cam 28 rotates in an empty load state through a gap of L/2 between the outer peripheral surface of the eccentric cam 28 and the left end of the adjusting screw shaft 36. After that, it comes into contact with the left end of the adjusting screw shaft 36, and the frame part 24
b, etc., to the right by L/2 to achieve the suction stroke. In this case, by providing the microgap α as described above, the reciprocating parts such as the frame portion 24b are moved to the right by the flow of the suction fluid on the diaphragm head side and the inertia of the movement of the reciprocating parts. Even if it is possible to stroke more than L/2, the range is only for the minute gap α, and this keeps the suction amount within the error range that is allowable for this type of reciprocating pump. This results in a constant suction stroke.

Furthermore, if the eccentric cam 28 continues to rotate clockwise in the discharge stroke shown in FIG. After rotating through the gap in an empty load state, it comes into contact with the reciprocating member 24,
Move the reciprocating member 24 etc. to the left by L/2~L/
2+αForcibly stroke the frame part 2
Attach the left end of cushion member 4b to stopper 46.
8, a constant magnitude discharge stroke can be obtained.

In other words, due to the "reverse screw pitch", the increase in the gap (empty load section) between the outer peripheral surface of the eccentric cam 28 and the left end of the adjusting screw shaft 36,
The decrease in the gap (stroke length) between the right end shoulder portion of the frame portion 24b and the left end portion of the stroke adjustment knob 42 can always be maintained in an equal relationship.

In the above, the case where the stroke length is adjusted to be reduced by 1/2 has been taken as an example, but the same applies to other stroke lengths.

[Effect of idea]

As is clear from the embodiments described above, according to the present invention, the eccentric cam is provided so as to act directly on a part of the reciprocating member whose one end is directly connected to the diaphragm,
Further, one end of an adjusting screw shaft for stroke adjustment is provided at the other end of the reciprocating member so as to face the eccentric cam, and the other end of the adjusting screw shaft is slid in the direction of these shafts using a stroke adjusting knob. The structure is simple because it is held movably and connected so as to engage in the rotational direction, and the threaded portions of the stroke adjustment knob and the adjustment screw shaft are arranged at equal pitches and in opposite threads. Moreover, the pump suction end can be positioned at the same time by adjusting the stroke once with the stroke adjustment knob.
It is possible to obtain a reciprocating pump drive device that can perform highly accurate stroke adjustment with simple operation.

Furthermore, according to the drive device of the present invention, not only can stroke adjustment be easily and smoothly achieved while the pump is being driven, but also when the stroke adjustment is less than the maximum stroke and immediately after the maximum discharge stroke, the eccentric cam is not able to move the reciprocating member. However, even in this state, excessive displacement of the reciprocating member in the suction stroke direction will cause the end of the reciprocating member and the end of the stroke adjustment knob to Since it is regulated by contact, even if abnormally high pressure occurs on the diaphragm head side, the suction stroke displacement remains constant, making it possible to always achieve appropriate stroke adjustment and high pump discharge accuracy. , the effect of contributing to improving the performance of this type of reciprocating pump is extremely large.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments.
For example, it can be applied as a drive device for various reciprocating pumps that do not use a diaphragm, and it goes without saying that various other improvements and changes can be made without departing from the spirit of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a reciprocating pump drive device according to the present invention, and FIGS. 2 to 4 are
FIG. 2 is a cross-sectional explanatory diagram of a main part showing the stroke adjustment state of the drive device shown in FIG. 1, in which FIG. 2 is a maximum stroke setting state, FIG. 3 is a 1/2 stroke setting state, and FIG. 4 is a 0 stroke setting state. are shown respectively. 10...Diaphragm head, 12, 14...
Ball valve, 16...Discharge pipe, 18...Suction pipe, 2
0...diaphragm, 22...coupling, 24...
Reciprocating member, 24a...rod part, 24b...frame part, 26...space part, 28...eccentric cam,
30... Rotating shaft, 32... Casing, 34...
Female thread part, 36... Adjustment screw shaft, 38... Thread end, 40... Shaft end, 42... Stroke adjustment knob, 44... Step portion, 46... Stopper, 48...
cushion parts.

Claims (1)

[Scope of utility model registration request] An eccentric cam is disposed so as to come into contact with a part of the reciprocating member whose one end is located on the side of the pump part during the pump discharge stroke, and the eccentric cam is screwed into the other end of the reciprocating member so as to be able to move forward and backward, and during the pump suction stroke. an adjusting screw shaft that comes into contact with the eccentric cam; a stroke adjusting knob that holds the adjusting screw shaft slidably in the axial direction and is coupled to engage in the rotational direction; and an electric motor that rotationally drives the eccentric cam. A reciprocating pump drive device comprising: a frame portion having a diaphragm coupled to the pump portion side of the reciprocating member, and a frame portion forming a space portion in which the eccentric cam is inserted and disposed on the opposite side; The stroke adjustment knob is adjustably arranged so as to come into contact with the end of the frame portion on the axis of the reciprocating member at the stroke end, and the screw of the adjustment screw shaft is screwed into the end of the frame portion. A drive device for a reciprocating pump, characterized in that the threaded portion of the stroke adjustment knob is arranged to have an equal pitch and an opposite threaded relationship.